As is commonly known, railway switch point assemblies include two rail end points which are tapered rail profiles capable of deflecting to move between two different positions in order to facilitate the correct alignment of the track components for the desired path of rolling stock transiting through the switch point assembly. The switch point assembly has two deflectable or movable rail end points which move in concert with one another between first and second alternative positions. In a first alternative position, a first one of these movable rail end points can be aligned with a first fixed stock rail to facilitate passage of the rolling stock straight through the switch point onto a first set of fixed rails. In a second alternative position, the second movable rail end point can be aligned with a second fixed stock rail to facilitate passage of the rolling stock onto a second set of fixed rails, such as to divert the rolling stock onto a siding.
In a typical switch point assembly, the two deflectable rail end points are moved by rods protruding from the opposite extremities of a unit often called a switch point machine. Inside the switch point machine, the rods are usually connected to a device with a reciprocating straight line motion, which is powered by a motor unit which is generally placed to the side of the rails. The state of the art includes numerous switch point machines for railway split point movements. Such mechanisms are normally installed at the switch point, and they are typically applied only to move the split rail end points of the switch point assembly.
Unless the switch is locked, a train coming from either of the converging directions may pass through the points, regardless of the position of the points, as the vehicle's wheels will force the points to move. Passage through a switch in this direction is known as a trailing-point movement.
In a trailing-point movement, the wheels will force the points to the proper position. This is sometimes known as running through the switch. If the points are rigidly connected to the switch control mechanism (e.g., a non-trailable switch machine), which is often desirable to ensure reliable operation, the switch mechanism's linkages may be bent, requiring repair before the switch is again usable. Certain switch machines may betrailable but are only acceptable for limited trailing forces and are only approved for limited speed, in stations or maneuver zones.
It may be desirable, therefor, to have a system and method that maintains the functionality of the switch point machine after trailing-point movements, without damage to the switch point assembly, switch point machine, fixed rails, etc.